Roller bearings that are in contact with a medium and are used, for example, in underwater applications, are exposed to continuous loads with the medium—here water—so that conventional roller contacts treated with synthetic or mineral lubricants are quickly washed away. Washing away such lubricants causes environmental problems, such as, environmental contamination due to eutrophication and the lack of biodegradability, especially for frequent or long-term use. To counteract the rapid loss of lubricant, dynamic seals of the intermediate space that is between the outer ring and inner ring and contains the roller contacts have been proposed in which a sealing unit is locked in rotation to the outer ring and inner ring on each side of the roller bearing and is sealed dynamically by means of a seal, for example, a lip seal. Here, moments of friction occur that adversely affect the efficiency of the roller bearing and thus of the application using the roller bearing.
Alternatively it is proposed to design roller bearings such that water acts as a lubricating medium. Here, very corrosion-resistant materials are required, especially in seawater environments. The load capacity of roller contacts lubricated only with water is comparatively low. Furthermore, so-called fouling must be taken into account, in which the roller contacts are obstructed with calcium-depositing microorganisms, wherein the roller contacts are permanently damaged.